Shaft protector



Sept. 18, 1945. .0 K, Q' E 2,385,000

' SHAFT PROTECTOR I Filed April 11, 1944 I fohzd/f/ az? ,dww

Patented Sept. 18, 1945 UNITED STATES PATENT OFFICE SHAFT PROTECTOR Roland K. Hoke, Baltimore, Md. Application Aprilll, 1944,'Se rial-N0. 530,487

7 Claims. (Cl.29 2 61,)

This invention is directed to a thrust unit for use in connection with puller assembliesof the wheel puller or other type, with such unit serving to avoid wear or distortion on the fixed element operated on by the puller, and to very materially reduce the frictional resistance between the operating parts in the use of the puller assembly.

The primary object of the present invention is to introduce into the conventional or other form of puller assembly a thrust unit to be interposed between the fixed element of the parts operated on by the puller assembly and the manually operable pressure bar of the puller assembly, with such unit having in part broad and relatively fixed contact with the fixed member of the parts operated on, and in part relatively fixed contact with the pressure rod of the puller assembly and including a thrust bearing between such parts of the unit, whereby the thrust rod in rotative movement to provide the puller function operates through the thrust bearing to transfer the power through that part of the thrust unit which is in relatively fixed relation to the fixed element of the parts operated on.

A further object of the invention is the provision of a thrust unit of the type described involving plugs separated by a thrust bearing and relatively rotatable, with one of the plugs having a relatively movable element for center cooperation with the fixed element of the parts being operated upon, and the other of the plugs having a relatively movable element to center and receive the end of the thrust rod, with both plugs forming broad contact surfaces in cooperation 'with the respective elements to distribute the load.

A further object of the invention isthe provision of means for insuring a spring-loaded yield of the movable elements in the thrust plugs to accommodate variation in the centers of the parts of the puller assembly with which the thrust plugs cooperate.

A further object of the invention is the provision of a roller thrust bearing between the plugs, externally sealed against leakage to permit the interior thereof to remain charged with appropriate lubrication to materially reduce frictional resistance in the operation of the puller assembly.

The invention is illustrated in the accompanying drawing, in which:

Figure 1 is a plan view illustrating the application of a conventional pinion puller with the improved thrust element in place.

Figure 2 is an enlarged vertical sectional view, partly in elevation, of the improved thrust unit.

In the particular type of puller assembly illustrated, and to which of course the invention is in nowise limited, such assembly includes hooks I pivotally connected at one end to a hub 2 formed with an internal threaded bore 3 to receive a thrust rod 4 threaded for cooperation with the bore of the ,hub and formed at one end with a center ;.,5 and at the opposite end, as at B, to receive an appropriate tool by which the thrust rod may be turned. The ends of the hooks I remote from the hub have the usual'terminal offset 1 to engage in rear, in the instance shown, of the pinion 8. l

, In the conventional use of such a puller, the hooks are positioned as illustrated in Figure 1, and the rod 4 is threaded through the bore until the center 5 engages an opening 5' in the end of resists the separation, relative thrust in opposite directions on the shaft 9 and pinion 8 results eventually in the removal of the latter from the shaft. This operation, necessarily including a relative rotative movement of the thrust rod against the shaft, tends to a distortion or damage to the end of the shaft and a frequent somewhat later distortion of the center 5. If the labor of removing the pinion compels a relatively high increased force to turn the thrust rod, the friction incident to the resistance becomes a very material factor in the difficulty of the removal, and obviously this resistance increases as the load increases. Y

It is the purpose of the present thrust unit to avoid this wear and distortion on the shaft 9 and to maintain at a minimum the frictional resistance incident to any required operation of the thrust rod.

To secure this result, the improved thrust unit includes spaced thrust plugs I0 and H disposed in alignment and each recessed at I2 on their proximate faces near their peripheral edges to receive races l3 of a roller or other bearing M. The races l3 fit more or less snugly within the recesses l2, with the races of a length however to leave an unoccupied margin I5 at the outer end of each recess. An unbroken steel plate It, which of course may be of any appropriate material, is

fitted into this unoccupied margin l5 of the recesses l2 to completely seal the thrust bearing against leakage.

The plug I0 is formed with an axial bore H, which at the bearing face of the plug is diametrically enlarged at [8 to provide an abrupt shoulder l9 surrounding the bore H. A center pin 20 is slidably fitted in the bore H and formed at one end with a conical point 2 I. The center pin has an annular projection 22 designed to fit in the bore enlargement l8 and bear against the shoulder I!) when the pin is in position to project the conical point the conventional distance beyond the opposite face of the plug H]. The plug H is formed witha bore 23 in axial. alignment with. the bore 11, which bore, is diametrically enlarged to approximately one-half its length at 24, for a purpose to be later referred to.

A centering pin 25 is slidably mounted in the bore 23 and formed at the end toward the. thrust bearing, with an annular projection. 26 to bea against the shoulder formed by the enlargement 24 of the bore 23, thus limitingmovementotthe; centering pin 25 in a direction from the thrust bearing. The end of the centering pin remote from the thrust. bearing, is axially, formed. with an appropriate center recess. 27. to receive the center 5 ot the thrust. rod A coil spring 28 is housed in the enlargement 24. of, bore; 2.3. and bearing. atone end against the center pin, and at the opposite. end, against, the centering pin25,

Aspreviously described, the. thrust roller. hearing is sealed against leakage to. the, ex erior thereof, and therefore it contemplated. as a mate.- rial part of the present, invention thatthe, space between the. proximate faces of the plugs. l and II and inwardly of the bearing proper. may be filled with grease or like lubricant;

In use, the thrust unit is interposed between the shaft 9 in the instance shown, and the opera.- tive end of the thrust rod, the conical end 2| of the center pin 20 fitting in the formed center opening of the shaft and thecenter ofthe thrust rod 4 fitting in. the center recess 2}! of the centering pin 25.. Of course, in the initial turning of the, thrust rod to hold; the thrustv unit in contact with the end of the shaft, the broad: outer face of. the thrust plug III will bear;v directly against the end of the shaft 9'; It the center opening in the shaft is insufficientto fully receive the conical point 21', the center-pin- 20 will yield against the pressure of the spring; until the broad face of the plug. l=0- is in direct a-Xi'al contact with the end of the shaft. the pressure movement of the thrust rod-4, the center 5 of that rod is fitted into therecess 27'of" the centeringpin 25, the latter yieldingif necessary until the broad proximate face of the plu It bears against the proximate faceof theend of-the thrust rod. With the hooks l engaged behind the pinion, the thrust rodis operated to thread it through the hub 2 and compel relatively oppo site movements: of the pinion and shaft; I'm this operation, the thrust rodof course isbeing turned, and as it is in contact with the face of the plug I I, the latter is also-turning; However; this turning movement of the plug H is not-.transmittedto theplug [0, but both the. relativerturningmouerment and the thrust are transmitted through and by the interposed roller bearing under constant and appropriate lubrication to the plug II). This plug l0, however, being. in contact with the fixed shaft 9, does not partake of the rotation but exerts a direct pressure on the end of the shaft without any relative movement between that shaft and the element of the puller assembly transmitting the pressure. Of course, continued movement of the thrust rod is necessary until the pulley is loosened on theshaft and thereafter easily removable, but no matter What the power required to operate the thrust rod may be, the friction incident to the turning of the thrust rod under that power is practically completely absorbed :by the roller bearing.

'I-heerfore, there is no mutilation of the end of the shaft 9, there, is substantially no friction or at least no increased friction incident to the operation of the thrust rod no matter what power may 'be required to remove that rod,. and. hence the puller assembly becomes an effective implement which will entirely avoid any distortion or mutilation of the end of the shaft, and Which Will materially simplify the effort required to. operate the assembly incident to the reduction inthe frictional component of that. operation.

What I claim is:

1;, A puller assembly thrust unit including spaced thrust plugs, an anti-friction thrustbearing between the plugs, a center pin movable in one plug, a centering pin movable in the other plug, and means operating through the thrust plugs and interposed thrust bearing. to, create the necessary removal pressure of the. unit.

2. A thrust unit including spaced plugs, an interposed antiefriction bearingv between the plugs, a. center pin movable in one plug, a centering pin movable. in the other plug, and. a.v spring interposed; between andv creating opposingpressures on the center pin, and the. centering. pin

3. A. construction as, defined in c1iaim.2 wherein each plug has a broad. bearing face providing opposed surfaces to take a thrust reaction.

4. A constructionas defined in. claim 2, whereinthe anti-friction bearing is. sealed against external leakage. to, provide. within the bearing a. lubricant space.

5... Aconstruction as. defined in claim 2,.wherein. races. of the,.anti-f-rictiorr bearing. are: seated in. recesses2 in the proximate faces ofv theplugs.

6.; A. constructionv as defined in. claim 2,.wherein thecente-r pin ismountedin an, axial. bore in one plug with the. bore formed with a shoulder and the center pin. formed with an annular en.- largement to engage said shoulder to move. the pin in. one. direction. relative to. the plug.

'7... A construction as. defined in claim 2,.wherein the plugreceiyinggthe centering. pin is formed with a boreain. which said pin. is slidable, with the bore. enlarged to house the spring. element between the center and centering pins..

ROLAND K; HOKE. 

